Transformer.



C. H. THORDARSON.

TRANSFORMER. APPLICATION FILED SEPT. 27. I915.

Patented May 21,1918.

,tion thereof, reference being electrical transformers,

PATENT OFFICE.

CHESTER H. THOBZDABSON, OF CHICAGO, ILLINOIS.

TRANSFORMER.

Specification of Letters ratent.

Patented May 21, 1918.

Application filed September 27, 1915. Serial No. 52,775.

To all whom it may concern:

Be it known that 1, son, a citizen of the United States, and a resident of Chicago, in the county of Cook and State of Illinois, have invented certain new and useful Improvements in Transformers; and I do hereby declare that the following is a full, clear, and exact descriphad to the acto the characdrawings, and

which companyin erence marked thereon,

ters of re form a part of this specification.

This invention relates to improvements in and refers to improvements in means for adjusting the transformer to p0 'tial drops along the transmission line, while at the same time maintaining the high and low tension windgs in magnetic balance against the force in of the ma netic flux between the windings A 'which ten s to spread the windings and to disru t the insulation.

-Ot er objects of the invention are to simplify and improve the construction of transformers, and the invention consists in the arrangement and combination of the parts shown in the drawings and described in the specification, and the invention is set forth in the appended claims.

Heretofore it has been a common practice in connecting adjustable transformers along a high tension line to cut out or isolate one or more of the end coils of the primary or secondary winding to correspond to the line drops, the coils thus cut out or isolated and also the next adjacent coils and the line being usually connected by tap-off wires to terminals, as at a terminal block, which wires are associated with bridging pieces or jumpers, so that one or more of the end coils may be cut out of the active circuit.

This practice has developed a defect in the operation of transformers in that it throws the primary and secondary windings out of magnetic balance thereby imposin unequal and excessive stresses on the win Cnnsran H. TEORDAR- nected. By thus arranging intermediate coils or winding units to be opened or cut out of the active circuit, 1 am able to maintain the output of the transformer substantially constant notwithstanding potential drops and, at the same time, to maintain the high and low tension windings in magnetic balance.

In the drawings Figure 1 is a fragmentary diagrammatic view of the high and low tension windings of a transformer, showing my improvements applied thereto.

Fig. 2 is a diagrammatic view of another type of transformer showing the adjusting feature of my improvements applied thereto,

Fig. 3 shows a modification of the wiring of the high tension winding.

Fig. 4 is a detail showing the manner of connecting the grounded tap-off conductor to the outer sides of the low tension windin coils.

As s own in the drawings, 10 designates the primary winding and 11 the secondary winding of a transformer. 12 designates the core and 13 diagrammatically indicates the insulation windings. In the type of transformer shown in Fig. 1, the primary winding is made 11 of a series of disk like units 14, 15, 16, 1% and 18 and the secondary winding may be made up of a series of like units 19, said units being formed, connected and insulated in a manner generally similar to the transformer construction shown in my prior application for U. S. Letters Patent, Serial No. 39,044, filed on the 10th day of July, 1915. It will be understood that in the diagrammatic illustration of the high tension units in Fig. 1 merely the upper cross sections of the coils or units are shown and that in the assembled structure the high tension winding coils surround the low tension windings and the core.

As shown in said Fig. 1, the adjustable feature of the transformer is arranged to cut or open four of the intermediate or central winding units 15, 16, 17 and 18 of the high tension winding. To the ends of each of the said units to be cut out and to adjacent active units of the rimary winding are connected tap-ofl' con uctors 20 which lead and are respectively connected to clips 21 mounted on a su1tably located terminal block 22. Said terminal clips are adapted to be bridged in pairs by bridging pleccs between the transformer are to be cut out of the active circuit the.

terminal clips are connected in series with the intermediate coils.o1"units, :so that the primary or high tension current traverses all of the coils or units of the primary Winding. If it beassuined that one of the winding units is to ,be opened or cut out of the active circuit, the bridging piece associated with terminal clips thereof will be disconnected from the associated 'clips and a longer bridging piece will be inserted between the terminal clips connected to the tap-oil wires of one of the active coils or units and that of the next adjacent adjusting coil or winding unit. The primary current will thereafter be diverted around the isolated coil or winding unit. In like manner two or more central or intermedi ate winding units may be cut out of the active circuit by bridging between the different terminal clips of the series. The outermost cl ps of the series are respectively connected to winding unlts or coils which are intended to always remain in thetctivo circuit.

In Fig. 2 my improvements are shown as applied to a type of transformer wherein thehigh and low tension windings; the latter not shownand the former designated by 25,

are wound upon two legs 26 of the magnetic circuit which are connected by end pieces or yokes '27. In this instance the central coils or turns of the high tension winding are connected to tap-oil conductors 28 to terminal clips 29 carried by the terminal block 30 and said terminals are adapted to be interconnected in the same manner as indicated in Fig. 1.

The foregoing illustrates the adaptation of my improved adjustment to two types of tL'zIllSfOl'lllQl'S, from which it will be clearly seen that the invention may be readily applied to other transformer types with the same result as to balancing the stresses due vto magnetic flux between the transformer w i ndings.

InEig. 3 is shown a modifiedarrangement of the tap-offconductors, designated therein as 35. In thisarrangement all of the con ductors but the central conductor-aremade tubular and the conductors are arranged in concentric relation with certain of the condoctors surroundingthe .othersand insulated by insulating sleeves 36. In this construction said conductors .are connected by wires 37 with the intermediate adjust ing coils and adjacent active coils of the high tension winding. The said tubular .condnctorsare adapted to be connected together by different length bridging clips 38 31) of the form shown in Rig. 3 so that the intermediate adjacent coils or windlng units may be connected in series or one or morerthereofrcnt-out-of,the series in the same general manner as heretofore indicated. nBieferring now to the low tension wind- .ing circuits and to the manner of connecting the same to the coils of the low tension winding and for connecting said coils or units with a grounded conductor, it will be noted that the coils or winding units 19 of the low tension" winding are connected in pairsin multiple between the circuitwires 40, 41 of the'low tension circuit. All the connections of the circuit wires to said coils are attheir inner ends,andin thefiatwire slab ,form' of winding unit'shown in my aforesaid prior application, said connections occur at the ,inner sides-of the ring like slab units. designates a grdunded" conductor that is'coniiected' to 'the outeesides of the "low tension windingnoils'pr units"l9,-the connection offsaid grounded'conductonto the 'said low tension windin'gkcoils being at the parts of said 'coils' nearest adjacent to the High tension winding. In this manner unjusuailstressesset up; in the low tensionwindling are readily idistrlbuted so as not to'pro- 'fduce destructi iiestresses 'in any'part of the winding. The arrangement shown provides 'fbetwee'n the high? and low tension windings an electrostatic shield which protects the low tension winding "from lelectrostatic stresses deueloped in the high 'tension' wind ing. ;said" s1ii ld is, ineflfect, dividedin'to a 1a rge number-of sectionsby reason of thejndependent connections of the'several coils or units with the circuit and grounded "conductors.

A neansof practically connectingtheoutsides of the coils 'or winding un'its to the groundedconductor 42'is shown in Fig. 4,

where said grounded conductorihas the form oi a'flat bar to which are soldered or otherwise secured the outer terminals-44 of said coils, adjacent coils being reverse'ly wound, as indicated in Fig. 4.

"The construction and arrangement whereby the low tension Winding. is protected from surges isjnot herein claimed but is made the vsub ect of a divisional application, filed "on the :23rd 'day of 'April, 1917, {Serial No. 163,865. 4 I

I claim s my invention:

1; An adjustable self-balancing transformercompris'ing a core, primary and secondary windings thereon, tap-ofi' (conductors connected 'to one or. more of theintermediate coils of one of the windings, said conduc- .tors being tubular, some of which are .in-

closed by others and separated by insulating tubes and interconnecting means to bridge across said conductors.

2. An adjustable self-balancing transformercomprisin a core, primary and secondary windings t ereon, tap-off conductors connected to one or' more of the intermediate coils of one of the windings said conductors being tubular, some of which are inclosed by others and separated by insulating tubes and interconnecting means to bridge across said conductors, the larger conductors being shorter than the contained smaller conductors and the insulating tubes being arranged to expose the ends of the conductors.

3. A series of take-ofl conductors for selfbalancing transformers and the like, some of which are tubular and surround the others, insulating tubes separating said conductors and arranged at their ends to expose the ends of the conductors, said conductors and tubes being progressively longer from the larger, 5

In testimony, that I claim the foregoing as 20 my invention I aflix my signature in the presence of two witnesses, this 28th day of August A. D. 1915.

CHESTER H. THORDARSON.

Witnesses:

W. L. HALL, G. E. Dowmn.

Copies of this patent may be obtained for live cents each, by addressing the "Commissioner of nmm, Washington, D. 0." 

